You really need to generate step and direction signals with either a micro or a 555. With the 555, generate a couple 100 hz square wave and then manually switch directions.
Also, make sure you've got the coils properly wired. You can tell which leads go the same coil by shorting them together - if the motor is harder to turn by hand then they are to the same coil. If its a unipolar motor then you will need to figure out the center tap.
By the way, with "manual excitation" (sounds kinky...) you should at least get at least a small jerk
Phil